Days After Incubation Research Articles

Iron (Fe) and zinc (Zn) coated urea application enhances nitrogen (N) status and bulb yield of onion (A. cepa) through prolonged urea-N stay in alkaline calcareous soil

Onion (A. cepa) is an important horticulture crop which is sensitive to nutrient limitations worldwide. Urea hydrolysis to ammonia (NH3) and carbon dioxide (CO2), due to soil urease activity, causes urea-N loss. Comparative to several commercial products, the potential use of micronutrient coated urea to reduce urea hydrolysis based NH3-volatilization losses is novel to-date. In this study, boron (B), iron (Fe), zinc (Zn) and copper (Cu) were coated on urea at their full or half recommended rates as (B)-half, (Fe)-half, (Zn)-half, (Cu)-half, (B)-full, (Fe)-full, (Zn)-full, (Cu)-full, (B+Fe)-half, (B+Zn)-half, (B+Cu)-half, (Fe+Zn)-half, (Fe+Cu)-half, (Zn+Cu)-half, (B+Fe)-full, (B+Zn)-full, (B+Cu)-full, (Fe+Zn)-full, (Fe+Cu)-full and (Zn+Cu)-full having gum-only coated urea as an internal control. Parallel to these, p-Phenylenediamine (PPD-0.2 %, 0.4 %, 0.6 %, 0.8 % and 1.0 %) and hydroquinone (HQ-0.5 %, 1.0 % and 2 %) coated urea treatments were also used with acetone-only coated urea as an internal control. Whereas the uncoated urea treatment was taken as an overall control. In pot experiment, the soil residual urea concentrations were increased by 2, 0.5, 1.85, 2.69 and 3.15 folds at 8 days after incubation (DAI), by 5.6, 1.89, 5.97, 0.54 and 6.23 folds at 12 DAI and by 119, 123, 155, 84 and 87 folds at 16 DAI under (B)-full, (B+Zn)-full, (Fe+Zn)-full, PPD-0.8 % and PPD-1.0 % coated urea treatments, respectively, as compared to uncoated urea. Among these five coating combinations, 54.26 % and 44.82 % bulb yield increments were observed under (Fe+Zn)-full and PPD-1 % coated urea, respectively, in comparison to uncoated urea in field experiment. However, the 33.33 % increment in nitrogen agronomic efficiency (NAE) and subsequent economic gains proved (Fe+Zn)-full coated urea application as a solution to address N losses in alkaline calcareous soils.

Impact of Paddy Straw Incorporation along with Different Fertilizer Doses on Mineral N Dynamics and GHG Emissions

Aim: An incubation experiment was conducted, which aimed to investigate NH4+ and NO3- release pattern and GHG emissions as influenced by paddy residue decomposition over 120 days. Study Design: Completely randomized block design. Place and Duration of Study: The study was conducted at Agrometerology laboratory, CRIDA, Hyderabad. The experiment was conducted between 2021-22. Methodology: Sampling was performed at 2, 4, 6, 8, 10, 20, 30, 45, 60, 75, 90, 105 and 120 days after incubation (DAI). The treatments included control (T1), soil + N (T2), paddy residue + 100% RDN (Recommended dose of Nitrogen) - 33:33:33 (T3), paddy residue + 100% RDN - 43:23:33 (T4), paddy residue + 100% RDN - 43:33:23 (T5), paddy residue + 10% extra RDN - 43:23:33 (T6). Fertilizer N was applied in three splits (first at initiation of experiment, second and third at 30 and 60 DAI respectively). RDN used in the study was 240 kg ha-1 (i.e., maize). Results: Residue incorporation along with inorganic fertilizer significantly influenced NH4+ - N and NO3- - N, as well as GHG emissions. After addition of each split, there was an increase in NH4+ - N and NO3- - N contents. Significantly higher NH4+ - N and NO3- - N was recorded in T6, compared to other treatments. The cumulative CO2 and N2O emissions were significantly higher in paddy residue + 10 % extra RDN – 43:23:33 i.e., 296.63 µg C g-1 of soil and 1.81 µg N g-1 of soil respectively, while lowest (42.59 µg C g-1 of soil and 0.09 µg N g-1 of soil respectively) was observed in control.

Morph-Cultural Variability among Different Isolates of Alternaria alternata Causing Leaf Spot of Ber (Ziziphus mauritiana Lamk) in Eastern Uttar Pradesh

Alternaria alternata is one of the most important foliar fungi causing leaf spot of ber. Leaf spot diseased samples were collected from different districts of Uttar Pradesh. Six different isolates of A. alternata were obtained in pure culture and designated as Aa1, Aa2, Aa3, Aa4, Aa5 and Aa6. The results revealed that there is a greater variation among different isolates of A. alternata. The maximum mycelial growth after 10 DAI (days after incubation) was found in Aa2 (90.10 mm) followed Aa5 (88.36) and Aa6 (86.53). Colony characters like color varied as greenish (Aa1), dark olivaceous green (Aa2), brown blackish (Aa3 and Aa6), brownish green with black center (Aa5), Greenish brown with white center (Aa4) and growth was slow (Aa4 and Aa5), medium (Aa1 and Aa6) and fast (Aa2 and Aa3). Growth appearance varied from fluffy (Aa1, Aa4, Aa5 and Aa6) and compressed (Aa2 and Aa3) with margin regular (Aa2 and Aa4) or irregular margin (Aa1, Aa3, Aa5 and Aa6). Sporulation was recorded in all six isolates but very good sporulation was observed in Aa2, Aa4 and Aa5. Highest average conidial length was recorded in isolates Aa4 (38.88μm) followed by Aa3 (30.20μm). Highest average width was recorded in Aa5 (15.06μm) followed by Aa3 (14.04 μm). Maximum beak length was observed in Aa2 (17.28 µm). The number of septa also varied among isolates. Maximum number of transverse septa was found in Aa5 (4-5). Maximum number of longitudinal septa was found in Aa5 (2-4).

Enhancement or Enrichment of the Vermicompost by Microbial Inoculation

The aim of this research experiment was enrichment of vermicompost by microbial inoculation for sustainable agriculture. An experiment was conducted to study the effects of different types of microbial species in various vermicompost treatments, along with varying quantities of microbes. Subsequently, 25 ml of each inoculant was applied per kg of wet-base vermicompost (VC) according to Busato et al. [1]. Vermicompost samples, each weighing one kg per treatment, were incubated in a well-aerated chamber at temperatures of 28 and 41ºC for a duration of 80 days. Throughout the incubation period, the moisture content of the VC samples was maintained at approximately 60 percent using water. Enriched VC treatments were subjected to chemical and biological analyses at intervals of 0, 20, 40, 60, and 80 days. An incubation study was conducted in the laboratory, involving the incubation of prepared enriched vermicompost (T1 to T7 treatments) with biofertilizers (T8 to T14 treatments) over an 80-day period. The content of N, P, K, and Zn was assessed at 0, 20, 40, 60, and 80 days after incubation (DAI). Among the various enriched vermicompost treatments, the highest total nitrogen content of 4.5% was observed in enriched vermicompost T11 after 80 DAI, followed by T9 (4.4%) and T14 (4.3%). The highest total phosphorus content of 4.9%, 4.7%, and 4.2% was respectively found in T11, T9, and T14 after 80 DAI. In terms of enriched vermicompost treatments, the highest potassium (K) and zinc (Zn) content (4.8% and 97.5 ppm, respectively) were observed.

In-field assessment of soil pH and mineralization of phosphorus and potassium following the application of composted winery solid waste in sandy loam Ferric Luvisol

Special attention on the plant nutrients mineralization rates is often required when organic fertilizers are used on croplands. This study described the patterns of phosphorus (P) and exchangeable potassium (K) released from winery solid waste (WSW) compost in sandy loam soil. Treatments consisted of equivalent rates of 0, 5, 10, 20 and 40 t ha-1 of compost-soil mixture in Ziplock bags buried on the field at 30 cm soil depth. Destructive sampling of treatments was conducted at 0, 7, 21, 42, 63, 84, 105 and 126 days after incubation (DAI) for laboratory analysis. The 40 t ha-1rate resulted in up to a 9.5% increase in soil pH while the contents of net mineralized P and K measured were significantly affected by compost rate and incubation period interaction. Over the 126 days of the incubation period that runs across summer and winter seasons, mineralized P ranged from -62 to 86 mg kg-1 whereas mineralized K varied between 41 and 2047 mg kg-1. Cumulative mineralized P and K contents ranged from 62 to 207 mg kg-1 and 1272 to 9206 mg kg-1, respectively with the highest amount obtained at the 40 t ha-1 compost rate. The high net P and K mineralized contents suggest that WSW compost may act as a P and K source. However, cautious use of WSW compost as a soil amendment is recommended to mitigate the potential risks of soil pH increases and other unintended consequences such as toxicity, nutrient imbalance, and possible P and K antagonistic effects. Keywords: Compost; Nutrient mineralization; Phyto-toxicity; Soil amendments

Effect of Temporal Variation in Mineralization of Nutrients through Sewage Sludge, Farm Yard Manure and Vermicompost in Soil

Soil amendment by organic matter (O.M.) has been widely accepted as an efficient nutrient-management technique in agriculture. The study was conducted as pot culture experiment at the Rajiv Gandhi South Campus, Barkachha Banaras Hindu University (B.H.U.) Mirzapur, which is located in the Vindhyan zone of Mirzapur district at 25º 10” latitude, 82º 37” longitude with an altitude of 427 meters above the sea level. The soils of the study region are mostly having poor fertility and shallow depth. Different sources of organic manures Sewage Sludge (S.S), Farm Yard Manure (FYM) and Vermi-Compost (V.C.) with different doses (10, 20 and 30 grams) were applied in pot along with soil and were incubated for 90 days. Required amount of water was added to soil in order to keep it moist as and when required. pH, electrical conductivity(E.C) , O.M. and nutrient content (N, P, K and S) had shown significant changes due to different treatments applied in soil. Applications of organic amendments in this study indicated considerable changes in the basic soil physio-chemical properties, different levels of available nutrient and their release pattern. With increase in doses of S.S and V.C. soil pH also increased but, it was decreased with increase in doses of FYM. Increase in the dose of S.S., F.Y.M. and V.C. had increased the E.C. and O.M. of soil. The available N content decreased with increase in the incubation interval. The available P increased from 30 Days After Incubation (DAI) to 60 DAI but it decreased at 90 DAI. Availability of S content increased with increase in duration of incubation period.

Incubation Studies to Find Out the Transformation of Different Fractions of Boron

An incubation study was conducted in the laboratory of College of Agriculture, Central Agricultural University, Manipur, India, to know the transformation of applied Boron (B) in soils at field capacity. Soil samples was collected periodically at 0, 30, 60 and 90 days after incubation (DAI) and analyzed for different fractions of B. The experiment was carried out under completely randomized block design (CRD). Altogether there were 6 treatment replicated thrice namely, T0= Control, T1= 0.5 mg B kg-1 soil, T2= 1 mg B kg-1 soil, T3= 1.5 mg B kg-1 soil, T4= 2 mg B kg-1 soil and T5= 2.5 mg B kg-1 soil. From the incubation experiment, it was inferred that with applied B, the organically bound B fraction was higher next to residual form when compared to other forms of B. At 30 days of incubation, different fractions of B showed an increasing trend for added levels of B compared to control due to recently applied B into the soil solution. However, at 60 and 90 days different fractions of B in the soil started decreasing due the fact that boron entered into tightly bound state within the soil. In general, B fertilization increased the availability of B content in soil and hence increased its availability to the crop. The sequence of the content of different fractions of B in an acid soils of Imphal-West district was readily soluble-B>organically bound-B>oxide bound-B> specifically adsorbed-B> residual-B.

Study of Release Pattern of Phosphorus in Soils: Incubated with Organic Acids and Different Origin of Rock Phosphate

In this study the hypotheses assumed was assessed through incubation study in lab. Soil samples were pre incubated at 25 °C for 1 week prior to actual incubation to stabilize the microbial activity. Moisture content of soil was adjusted to 60 % of water holding capacity by adding deionized water. There were three Rock Phosphates of origin Jhabua, Udaipur-I, Udaipur-II and eleven treatments including the control and soils were analysed at six incubation periods (15, 30, 45, 60, 90 and 120 days); with three replications to see the effectiveness of different RPs treated with organic acids and zeolite with phosphate solubilizing bacteria (PSB) viz., Pseudomonas fluorescence. The incubation experiment showed a positive impact of the organic acids and FYM with increasing days of incubation gaining highest peak at 60 days in their ability to release P from all the RP sources. Data from 45 to 60 Days After Incubation (DAI) were found most suitable for P availability point of view. URP II showed maximum available P with gluconic acid@20 mM (13.28 kg ha-1) with an increase of 39% followed by FYM @5 tonne ha-1 with available P (13.10 kg ha-1) and increase of 50.97% over control. JRP responded maximum with FYM @ 5 tonne ha-1(9.05 kg ha-1) available P with an increase of 36.35% followed by oxalic acid. The URP I maintained highest available P with oxalic acid@0.5 M (10.59 kg ha-1) with an increase of 44.51% followed by FYM @5 tonne ha-1.

SHOLI KOLLEKTSIYASI NAV VA NAMUNALARINING PAST HARORATDA UNIB CHIQISH KO‘RSATKICHINI BAHOLASH

The article examines and analyzes germination of seeds of varieties and samples of rice collection of the Rice Research Institute, at low temperatures (15° C). According to the findings, the local variety of rice - ‘Iskandar’ taken as a test pattern, showed a higher germination rate at a low temperature than other tested and collection varieties. In this test pattern, the germination rate reached 17% within 3 days after incubation (DAI), while in 6 DAI it achieved 92%. Within 6 days after incubation, the germination rates in Mustaqillik, Lazurniy, and Tarona varieties were found to be 67%, 48%, and 30%, respectively, whereas within 8 DAI these achieved the range of 60-90%. Out of a total of 230 collection varieties and samples with germination rates of above 90%, there were 57% on the 7th incubation day and 93% on the 8th incubation day.

ISOLASI DAN UJI ANTAGONIS BAKTERI ASAL TANDAN KOSONG SAWIT YANG DIAPLIKASIKAN PADA AREAL TANAMAN KARET TERHADAP PENYAKIT JAMUR AKAR PUTIH (R. microporus)

The concern of oil palm empty fruit bunches (OPEFB) utilization in the rubber field that potential to be a host of white root disease needs to be deeply investigated. The objective of this study was to assess the bacteria on the surface of OPEFB that able to inhibit the growth of R. microporus fungi. The antagonistic assay of eight isolates of bacteria against R. microporus fungi was conducted in the Plant Protection Laboratory of Sungei Putih Research Centre. The isolates were isolated from the surface of OPEFB applied in the rubber field. Nutrient agar (NA) was employed in the isolation and purification of bacteria. The antagonistic assay was carried out in vitro using the dual culture method. The observation was performed on 2, 4, 6, and 8 days after incubation (DAI). The result indicated that the eight isolates have varied in inhibition ability of R. Microporus fungi. The initial inhibition was started since 2 DAI particularly in the isolates B2, B3, B4, and B7. The percentage of inhibition were 30%, 60%, 65% dan 69% respectively. Until 8 HSI, the isolates B2, B3, B4, B6, B7, and B8 were still inhibiting the growth of R. microporus fungi > 80%. The isolates B3 and B4 showed the best performance in fungi inhibition with the percentage > 95%. Whereas, the ability of inhibition of the isolates B1 and B5 were very low as < 50%. The existence of such antagonistic bacteria perhaps led to OPEB was not role as the host of white root disease while applied in the rubber field

Functional evaluation of culture filtrates of Bacillus subtilis and Pseudomonas fluorescens on the mortality and hatching of Meloidogyne javanica.

Rhizospheric bacteria Bacillus subtilis and Pseudomonas fluorescens are two widely tested biological control agents against root-knot nematodes (RKN) of different crops. However, their performance as bio-control agents varies with their place of origin. Culture filtrates of rhizospheric bacteria contain some intermediary metabolites that have nematicidal activity. An in vitro experiment was undertaken to evaluate the functionality of culture filtrates of B. subtilis (MN252542.1) and P. fluorescens (MN256394.1) at different concentrations (1.0%, 2.5%, 5.0%, 7.0%, 10.0% and 25.0%) on the hatching and mortality of Meloidogyne javanica at different time span. Bacterial strains were isolated from rhizospheric soils of Bangladesh. At three days after incubation (DAI), 25.0% concentration of culture filtrates of both B. subtilis and P. fluorescens showed 100.0% mortality of second stage juveniles (J2) of M. javanica. Additionally, 25.0% concentration of culture filtrates of both bacteria showed 100.0% inhibition of hatching at one week after incubation (WAI). A decreasing trend in hatching of M. javanica was observed with the increment of the concentration of culture filtrates and progression of incubation time. The findings of this experiment reveal that culture filtrates of these accessions of B. subtilis and P. fluorescens are effective for controlling M. javanica and would be potential candidates for developing bio-nematicides.

Expression regulation of MALATE SYNTHASE involved in glyoxylate cycle during protocorm development in Phalaenopsis aphrodite (Orchidaceae)

Orchid (Orchidaceae) is one of the largest families in angiosperms and presents exceptional diversity in lifestyle. Their unique reproductive characteristics of orchid are attracted by scientist for centuries. One of the synapomorphies of orchid plants is that their seeds do not contain endosperm. Lipids are used as major energy storage in orchid seeds. However, regulation and mobilization of lipid usage during early seedling (protocorm) stage of orchid is not understood. In this study, we compared transcriptomes from developing Phalaenopsis aphrodite protocorms grown on 1/2-strength MS medium with sucrose. The expression of P. aphrodite MALATE SYNTHASE (PaMLS), involved in the glyoxylate cycle, was significantly decreased from 4 days after incubation (DAI) to 7 DAI. On real-time RT-PCR, both P. aphrodite ISOCITRATE LYASE (PaICL) and PaMLS were down-regulated during protocorm development and suppressed by sucrose treatment. In addition, several genes encoding transcription factors regulating PaMLS expression were identified. A gene encoding homeobox transcription factor (named PaHB5) was involved in positive regulation of PaMLS. This study showed that sucrose regulates the glyoxylate cycle during orchid protocorm development in asymbiotic germination and provides new insights into the transcription factors involved in the regulation of malate synthase expression.

Rice straw and composted azolla alter carbon and nitrogen mineralization and microbial activity of a paddy soil under drying–rewetting cycles

Alternate drying–rewetting, as a type of irrigation regime, can influence carbon (C) and nitrogen (N) transformations and microbial activity in soils under the application of organic amendments, but such effects have seldom been explored in paddy soils amended with organic matters with various C:N ratio. The objective of the present study was to investigate the effect of composted azolla (azocompost) with a low C:N ratio (11) and rice straw with a high C:N ratio (42) on soil C and N changes, the enzymes effective at the transformations of these nutrients, soil respiration, and microbial biomass in paddy soil under drying–rewetting cycles during a 60–day incubation experiment. Experiment treatments included: organic amendment factor at three levels (i) unamended soil (control); (ii) soil amended with 1.5% azocompost; and (iii) soil amended with 1.5% rice straw and irrigation regimes factor at three levels (i) constant soil moisture in a waterlogged state (ConstM); (ii) mild drying–rewetting (MildM); and (iii) severe drying–rewetting (SevM). Drying–rewetting decreased respiration rate (by 40%), dissolved organic carbon (by 40%), microbial biomass carbon (by 75%), NH4+ concentration (by 21%), urease activity (by 55%) and C/N ratio (by 1%) of unamended soil under SevM conditions. However, the rice straw amendment increased the same factors under the same conditions. Drying–rewetting decreased NO3− concentration by 35% in control while azocompost increased it by 78%. Drying–rewetting events significantly increased cumulative CO2–C in soils amended with rice straw under all irrigation regimes at 30 days after incubation (DAI). The maximum and minimum soil respiration rate was observed in soil amended with rice straw under MildM conditions (83% increase compared to control) and unamended soil under SevM conditions, respectively. The highest microbial biomass carbon and microbial biomass nitrogen were registered in soil amended with rice straw under MildM conditions at 15 DAI and in soil amended with azocompost under ConstM conditions at 60 DAI, respectively. The C:N ratio had the highest correlation with other measured carbon and nitrogen indicators. It can be concluded that the effectiveness of organic amendments on biochemical changes of C and N in the short–term, which strongly depended on their C:N ratio, was greater than that of irrigation regimes.

Seed-borne infestation and management of Alternaria Species in mustard seed at Chitwan district, Nepal

Alternaria blight in mustard cause heavy damage to the foliar parts resulting into poor growth and development of plants and thereby reduces seed yield. Inorder to manage Alternaria infestation in mustard seed for yield maximization, an experiment was conducted in the plant protection laboratory in Nepal Polytechnic Institute, Bharatpur, Chitwan in 2018, using Completely Randomized Design (CRD) with four replicates. Five treatments i.e.Uthane M-45 (2g/kg), Neem powder (3 g/kg), Bojho powder (4g/kg), Trichoderma harzianum, (107 Conidia/mL) and control (without treatment) were used for seed treatment of local variety of Mustard. Four hundred seeds for each treatment (25 seeds in each petriplate) were plated using triple layers of moistened blotter paper in petriplate and incubated at (27±20C) for 2 days and followed deep freezing for 24 hrs. Data of disease incidence and seed germination were recorded in 3, 7 and 10 days after incubation (DAI). Seedling vigor and seedling weight were also recorded at 5 DAI. The percentage of Alternaria spp incidence on seeds at different DAI showed highly significant with respect to different treatments. Application of Uthane M-45 and T. harzianum significantly reduced the seed-borne infection of Alternaria spp. as compared to control. At 3 DAI Uthane M-45 completely checked the pathogen however, only 4% and 5% disease incidence was observed in 7 DAI and 10 DAI respectively. Bio control agent Trichoderma harzianum was found next best alternative after Uthane M-45 to control disease. Plant extract Bojho powder and Neem powder were found better than control to check the disease. Furthermore, highest germination (76%) was observed in Trichoderma treatment whereas, lowest germination was found in control.

Impact of Nitrogen Amendments on Soil Enzyme Dynamics under Simulated Wetland Ecosystem

Aims: To evaluate the influence of nitrogen amendments on soil enzyme dynamics in a long term incubation experiment.
 Study Design: An in vitro simulated wetland ecosystem designed with rhizosphere soil was enriched with different N sources.
 Place and Duration of Study: The study was conducted at Biocatalysts Laboratory, Tamil Nadu Agricultural University, Coimbatore, India. An incubation experiment ran for 150 days, to determine the temporal changes of soil enzyme activities.
 Methodology: There were five treatments replicated thrice. The N enrichment included in the treatments were aerated except S1 as detailed below: rhizosphere soil (S1), rhizosphere soil without enrichment (S2), combined NH4Cl and KNO2 enriched rhizosphere soil (S3), KNO2 enriched rhizosphere soil (S4) and NH4Cl enriched rhizosphere soil (S5).
 Results: The soil enzymes such as dehydrogenase (24.59 μg TPF g-1 soil day-1), urease (49.27 μg NH3 g-1 soil) and acid phosphatase (38.57 μg PNP g-1 soil h-1) were observed maximum in NH4Cl enriched rhizosphere soil (S5) on 70 DAI (days after incubation). While, highest alkaline phosphatase (53.40 μg PNP g-1 soil h-1) and fluorescein diacetate (7.57 μg fluorescein g-1 soil h-1) were registered on 70 DAI in KNO2 enriched soil (S4) and KNO2 + NH4Cl (S3) respectively. However, all the enzyme activities, irrespective of treatments, showed an increasing trend up to 70 DAI and thereafter, declined gradually.
 Conclusion: Enzyme activities registered maximum in NH4Cl enriched rhizosphere soil (S5) than other enrichments. Basal N application as ammoniacal form (NH4+) triggers efficient trade-offs between soil functions in the wetland ecosystem whereas, combined sources contribute to microbial biomass and redox status of soil.

PENGARUH APLIKASI BOKASHI TERHADAP DINAMIKA KETERSEDIAAN N, P, DAN S PADA INCEPTISOL KARANGPLOSO, MALANG

The Inceptisol of Karangploso has low soil pH, low organic matter (OM), medium total soil N, very low C/N ratio, and low available sulphur - that cause low soil productivity. The application of bokashi preserves strongly productivity and organic matter in the soil. This research aimed to determine the effect of bokashi application in improving soil chemical properties and N, P, S-available in an Inceptisol of Karangploso. The experiment was conducted in greenhouse of Facultyof Agriculture, Brawijaya University using a completely randomized design with 7 treatments and 3 replications. The treatments consisted of O 1 = dose of 5 t ha -1 + ½ A, O 2 = dose of 10 t ha -1 + ½ A, O 3 = dose of 15 t ha -1 + ½ A, O 4 = dose of 20 t ha -1 + ½ A, O 5 = dose of 25 t ha -1 + ½ A, and O 6 = dose of 30 t ha -1 + ½ A. The results showed that the increasing dose of bokashi significantly increased soil pH (from 5.1 to 5.4), C/N ratio (from 9.64 to 9.93), P-available (from 141 to 142.6 ppm P) at 60 DAI (days after incubation), total N (from 0.21 to 0.24% at 30 DAI and 0.18% to 0.24% at 60 DAI ) and NO 3 - (from 24.96 to 65.47 ppm at 30 DAI and 14.91 ppm to 39.20 ppm at 60 DAI) compared to the control, but it had no significantly effect on organic carbon, OM, SO 4 2- in soil. The correlation test showed that there was a strong and positive correlation between pH and NO 3 - (r=0,77*), organic carbon and NO 3 - (r=0,63), organic carbon and P-available (r=0,78*), OM to NO 3 - (r=0,70*), and OM to P-available (r=0,86*).

Release of Nitrogen and CO2 evolution from Manures and Fertilizers applied in Soil: An incubation study

Carbon and nitrogen mineralization and urease activity were evaluated under wet and dry climate with input of manures and fertilizers. Results indicates that release of NH4+ and NO3N and CO2 evolution was maximum during 7 to 21 days after incubation (DAI) with recommended dose of fertilizer and decreased later on. Release of N and C took place after 21 DAI where manures applied either with neem cake or fertilizers. The evolution of CO2C and total nitrogen were significantly higher in poultry manure combined with neem cake and FYM as compared to vermicompost along with neem cake. The NH4+N released during the entire incubation period were higher than NO3N. Combination of neem cake, poultry manure and FYM had higher enzyme activity than other treatments. Application of commercial fertilizers registered significantly higher CO2C fluxes upto 35 DAI compared to manures and control. Overall effect of manures applied with neem cake or their combination proved better in the treatments for release of nitrogen. Correlation study between CO2C flux, total N and urease activity showed that a positive relationship (p<0.05) with each others.

First Report of Stem Canker Caused by Fusarium solani on Tectona grandis in China

Teak (Tectona grandis Linn. f.), belonging to Lamiaceae, is one of the most precious timber species. In May 2015, a severe canker was found on stems of teak saplings in an orchard in Pubei County, Guangxi Province, China. Twenty-seven percent of saplings (about 7 cm diameter at 1.4 m height) were infected in this site (2 hectares) and the disease was also found in four otherorchards in Guangxi. The bark of infected stems first turned brown, then became gray followed by cracking. As lesions expanded, sunken cankers appeared and eventually the tree died. Stems of diseased plants took a red color. On potato dextrose agar (PDA), a fungus was isolated from 92% of 25 samples collected on the stem of three cankered saplings. Samples were surface sterilized in 75% ethanol for 30 s and then in 2.5% sodium hypochlorite for 2.5 min. The colonies on PDA showed sparse white mycelium. Microconidia, produced 7 days after incubation (DAI) at 25 °C on PDA, were oval, ellipsoid, reniform, fusiform and aseptate, 5.12 to 12....

Impact of Aquatic Earthworms on Methane Emission Reduction from the Paddy Field Soil in Japan

Methane (CH4) is one of the major greenhouse gases that significantly contributes to global warming. Therefore, substantial efforts are being made to reduce CH4 emissions. Paddy fields make a major contribution to atmospheric CH4 concentration because of their anoxic soil environment. Paddy field is habitat of many aquatic earthworms which can play a crucial role in reducing CH4 emissions from paddy field, because their bioturbation activities influence the soil structure and increase oxygen penetration and hence the activity of methanotrophs. Therefore, it was hypothesized that aquatic earthworms may accelerate oxidation of CH4 through their bioturbation activity. This incubation study evaluated the effects of earthworms on the activity of methanotrophs. Soil was incubated with a full factorial combination of two levels of aquatic earthworm (with and without earthworm) and two levels of fertilizer (with and without urea) for 35 days. The addition of urea increased the earthworm density in paddy soil by nearly doubled of without urea. At 28 days after incubation (DAI) the CH4 flux decreased from 2055 mg m-2 h-1 in only urea received soil to 425 mg m-2 h-1 in soil received both urea and earthworm treatment. Phospholipid fatty acid analysis showed that the presence of aquatic earthworms contributed to an increase in the biomass of methanotrophs. The study implies that aquatic earthworms may play vital role to reduce CH4 emission form paddy fields by creating favorable environment for methanotrophs, even in the soils fertilized with urea.

Documentation of five potassium- and phosphorus-solubilizing bacteria for their K and P-solubilization ability from various minerals

Abstract The ability of a few soil bacteria to transform unavailable forms of phosphorus (P) and potassium (K) to an available form is an important feature in plant growth-promoting bacteria for increasing crop yields of high- P and K-demand crops. In this research, screening and characterization of thirty-five K-solubilizing bacterial (KSB) and P-solubilizing bacteria (PSB) isolate which were evaluated for their ability to solubilize K and P from the waste muscovite (WM), waste biotite (WB), tri-calcium phosphate (TCP) and rock phosphate (RP) by analyzing the soluble P and K content after 7, 14, 21 days after incubation (DAI) at 28±2 °C on MABs (Modified Aleksandrov Broths) and Pikovskaya's medium. The soluble P and K contents in all isolates were significantly (p